**EXHIBIT 12.1****CERTIFICATION PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002**I, Prof. Dr. Henning Kagermann, certify that: 1. I have reviewed this Annual Report on Form 20-F of SAP AG;  2. Based on my knowledge, this report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statements made, in light ofthe circumstances under which such statements were made, not misleading with respect tothe period covered by this report;  3. Based on my knowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financial condition, resultsof operations and cash flows of the company as of, and for, the periods presented in thisreport;  4. The company’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined inExchange Act Rules 13a-15(f) and 15d-15(f) for the company and have: a. Designed such disclosure controls and procedures, or caused suchdisclosure controls and procedures to be designed under oursupervision, to ensure that material information relating to thecompany, including its consolidated subsidiaries, is made known tous by others within those entities, particularly during the periodin which this report is being prepared;  b. Designed such internal control over financial reporting, or causedsuch internal control over financial reporting to be designed underour supervision, to provide reasonable assurance regarding thereliability of financial reporting and the preparation of financialstatements for external purposes in accordance with generallyaccepted accounting principles;  c. Evaluated the effectiveness of the company’s disclosure controls andprocedures and presented in this report our conclusions about theeffectiveness of the disclosure controls and procedures, as of theend of the period covered by this report based on such evaluation;and  d. Disclosed in this report any change in the company’s internalcontrol over financial reporting that occurred during the periodcovered by the annual report that has materially affected, or isreasonably likely to materially affect, the company’s internalcontrol over financial reporting; and 5. The company’s other certifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the company’s auditors andthe audit committee of the company’s board of directors (or persons performing theequivalent function): a. All significant deficiencies and material weaknesses in the designor operation of internal control over financial reporting which arereasonably likely to adversely affect the company’s ability torecord, process, summarize and report financial information; and  b. Any fraud, whether or not material, that involves management orother employees who have a significant role in the company’sinternal control over financial reporting.        Date: April 2, 2007   /s/ HENNING KAGERMANN    Name:  Prof. Dr. Henning Kagermann    Title:  Chief Executive Officer